JavaScript Math Random method returns a random number (floating) between 0 (inclusive), and 1 (exclusive). To get the integer number you have to use Math.floor() function with it.
Example: How to use Math.random()
<!DOCTYPE html>
<html>
<body>
<p id="result"></p>
<script>
document.getElementById("result").innerHTML = Math.random();
</script>
</body>
</html>
Output:
Q: How to Generate Random Whole Numbers with JavaScript?
Answer: It’s easy and useful to generate random decimals or whole numbers. See below steps to do get the whole number:-
- Use
Math.random()to generate a random decimal. - Multiply that random decimal by 100 or any number.
- Use another function,
Math.floor()to round the number down to its nearest whole number.
Math.floor(Math.random() * 100);Complete Example and Programming code:-
<!DOCTYPE html>
<html>
<body>
<p id="result"></p>
<script>
function randomWholeNum() {
// Only change code below this line.
return Math.floor(Math.random() * 100);
}
document.getElementById("result").innerHTML = randomWholeNum();
</script>
</body>
</html>
How to return random integers between the given range?
Answer: See below code for Returns a random integer from.
0 to 9
Math.floor(Math.random() * 10);0 to 10
Math.floor(Math.random() * 11);0 to 100
Math.floor(Math.random() * 101);Math.floor(Math.random() * 101);10 to 100
<!DOCTYPE html>
<html>
<body>
<p id="result"></p>
<script>
function randomWholeNum() {
var min=10;
var max=100;
var random = Math.floor(Math.random() * (+max - +min)) + +min;
return random;
}
document.getElementById("result").innerHTML = randomWholeNum();
</script>
</body>
</html>
Supported Browsers: The browsers supported by JavaScript Math.random() function are listed below:
- Google Chrome
- Internet Explorer
- Firefox
- Opera
- Safari
Do comment if you have any doubts and suggestions on this tutorial.
Note: The All JS Examples codes are tested on the Safari browser (Version 12.0.2) and Chrome.
OS: macOS 10.14 Mojave
Code: HTML 5 Version